The budget-friendly benefits of a mixer rebuild schedule

Posted by Megan Thompson on Sep 16, 2020

Eat your vegetables. Pay your taxes. Rebuild your gypsum pin mixer before it gets too worn down.

It’s not the most fun advice, but we give it for good reason! ACS Mixers will rebuild your mixer so it runs like new. Compared to the cost of buying brand-new, this approach can be significantly cheaper.

It also saves time and effort. Keep in mind this is only possible if you’re keeping up with proper maintenance and sending your mixer in for a rebuild at regular intervals.

We recommend rebuilding your mixer every 8 months to a year. The short explanation: a mixer rebuild is usually easier, more economical and faster than a full build. The technical reasons and telltale signs of wear will help you understand why that is.

Why 8 months to a year?

That’s a general range we recommend, but it will all depend on the type of rock you have and how much it wears down your machine. Some materials are more abrasive and wear down the parts faster than softer, smoother ones.

It also depends on how often you perform maintenance on the mixer. ACS’ resident gypsum expert, Gypsum Sales and Consulting Manager Wayne Beveridge, says a regular maintenance and rebuild schedule can save you a lot of money on unnecessary repairs. He uses the mixer’s rotor as a prime example.

“The rotor is the most expensive part of the mixer, but it is not rebuildable,” he explains. “If you leave it too long without maintenance, the rebuild will be much more expensive.”

That’s because the rotor is essentially a piece of stainless steel that has been CNC-machined to a precise shape and size, then polished by hand. Without its protective chrome coating, the rotor quickly loses its edge and stops functioning properly.

“Chrome is like your armor plating. As soon as material eats through the armor, it gets right through to the meat,” Beveridge explains. “Without a chrome coating, stainless steel warps like a hockey stick. You can only apply so much heat before it distorts and becomes a hunk of scrap.”

To avoid this, he recommends rebuilding just before you lose the chrome on the front edges of your rotor coating. “That’s where a lot of wear happens.”

Telltale signs you need a rebuild

Worn-down chrome is one of the key signs to watch for in your mixer, especially on the rotor. Once the stainless-steel underneath is worn too much, it’s not possible to get back the precise edge or shape needed for the mixer part to work properly. Rotor replacement is then required, as large repairs will warp the stainless-steel rotor.

For similar reasons, it’s important to check for wear on the rim liner, which protects the mixer rim. It’s replaceable but costly and time consuming, and leaving it too long can cause other parts of the mixer to become damaged, such as completely wearing through the carbon steel rim. This would be a total neglect situation, but we have seen this more than once.

The bottom bearing seals can rust and deteriorate if they’re left unchecked and poorly lubed. This would be a major repair situation if left to failure as well.

The lid lump ring is another one to check for wear. The lid lump ring and rotor lump ring work together to control the maximum size of lumps that are released from the mixer, so they should be kept in good condition.

“You cut the rebuild cost significantly just by keeping up the schedule,” says Beveridge. That’s because you’re getting ahead of damage before it’s unfixable, allowing technicians to refurbish what you have instead of buying new parts. “The more parts you save, the faster, easier and cheaper it will be to rebuild.”

What happens in a mixer rebuild?

The type of work done in a rebuild varies, but generally it involves re-chroming and polishing any salvageable parts and otherwise repairing or replacing any broken parts.

Once the work order comes in, ACS technicians will conduct an assessment. They take apart the mixer, part by part, and lay everything out to assess the condition of each part. Anything that is salvageable will be priced out accordingly, depending on the time it will take, and potentially get repaired or polished and re-chromed. Replacements may include a new rotor lump ring, pins, scrapers, bearings and seals, to name a few possibilities. Once everything is assessed and documented, the quote goes back to the customer, who will have an opportunity to review and order a replacement mixer if they prefer.

When the mixer leaves our shop, it looks virtually the same as it did when you first got it. Aside from a few possible dings on the aluminum lid, it is fully painted and looks brand-new.

If you stay on top of regular maintenance, it should last you another 8 months to a year. We used Beveridge’s expertise to write up a handy guide to weekly mixer maintenance — it mentions rotor pins, lid pins, scrapers and other parts you should check on each week to keep your mixer in great shape.

Let’s start rebuilding!

Want to set up a regular mixer rebuild schedule? It’s best to take care of them before they get knocked out of service. Call an ACS Mixers rep to get started.

Posted By Megan Thompson President & COO of ACS Valves

Think your plant is safe from fires? Ask our residential NFPA expert, Megan, and she may tell you otherwise. Though her personality has plenty of spark, she’s invested her 26 years of experience in the industry to helping prevent explosions in plants like yours—and can tell you just what you need to keep your workers safe.

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